As more and more information is moving into electronic form, encryption is becoming more common. One prior art method of encryption is public key encryption, an encryption scheme in which each person gets a pair of keys, called the public key and the private key. Each person's public key is published while the private key is kept secret. Messages are encrypted using the intended recipient's public key and can only be decrypted using the recipient's private key. Messages are signed using the sender's public key and can only be decrypted using the sender's public key. The need for sender and receiver to share secret information (keys) via some secure channel is eliminated--all communications involve only public keys, and no private key needs to be transmitted or shared. Public-key cryptography can be used for authentication (digital signatures) as well as for privacy (encryption). Other encryption schemes, such as symmetric key encryption rely on an exchange of keys.
However, keys generally are 64 bit numbers or larger and users do not memorize their keys. Rather, users store their key on their computer system. Because computer systems are rarely truly secure, the key may be taken from a computer system. In order to prevent this, the key may be stored in a password protected file. However, passwords may be broken. Additionally, the system is only as secure as the least secure level. Therefore, what is needed is a secure cryptographic key that is easily usable by the user, but not accessible to third parties.